Method and blank for forming a package within a wrapping

ABSTRACT

A method and blank for forming an overwrapped package that is impervious to atmospheric moisture and vapor. The package is formed from a blank having a substratum of relatively stiff package-forming material on the exterior of which is secured a protective sheeting of moisture impervious material that is secured to the substratum by an adhesive of low melting point that is likewise moisture impervious and may be delaminated from the substratum by the application of heat. The method includes the steps of delaminating areas of the blank, folding the substratum of the delaminated area away from the sheeting and then folding the delaminated sheeting against the exterior of an adjacent portion of the blank.

United States Patent Silver METHOD AND BLANK FOR FORMING A PACKAGEWITHIN A WRAPPING [75] Inventor: Stanley M. Silver, London, England [73]Assignee: Paxall, Inc., Chicago, 111.

22 Filed: Dec. 18, 1972 [21] Appl. No.: 316,238

Paulsen 229/37 R 3,040,963 6/1962 Turpin 229/14 BL 3,152,694 10/1964Nashed et al...... 206/632 3,191,845 6/1965 Wainberg 229/32 [451 Apr.15, 1975 3,411.694 11/1968 Silver 229/37 R 3.560.223 2/1971 Turbak99/109 3,572,576 3/1971 Foster 229/31 [57] ABSTRACT A method and blankfor forming an overwrapped package that is impervious to atmosphericmoisture and vapor. The package is formed from a blank having asubstratum of relatively stiff package-forming material on the exteriorof which is secured a protective sheeting of moisture imperviousmaterial that is secured to the substratum by an adhesive of low meltingpoint that is likewise moisture impervious and may be delaminated fromthe substratum by the application of heat. The method includes the stepsof delaminating areas of the blank, folding the substratum of thedelaminated area away from the sheeting and then folding the delaminatedsheeting against the exterior of an adjacent portion of the blank.

13 Claims, 10 Drawing Figures METHOD AND BLANK FOR FORMING A PACKAGEWITHIN A WRAPPING The present invention relates to a method of and blankfor forming a package, such as a box or carton and, more particularly.to such a method and blank for forming such package that will maintainits contents hermetically sealed against environmental effects, such asmoisture, odors or the like, and is a variation and extension of myinvention described and claimed in my US. Pat. No. 3,411,694.

The invention of my said patent is concerned with boxes or cartons whichform a barrier against leakage of their contents, both liquid andgaseous, to the exterior. The present invention is directed to theprovision of a method and blank for forming packages which bar thepenetration into their interior of atmospheric moisture or vapor thatmight adversely affect the contents of the package and its walls.

Heretofore, endeavor has been made to protect contents of packagesagainst, and the weakening of its walls by, the effects of atmosphericmoisture by an overwrap of a film or foil, either loose or tight. Manysuch overwraps, as heretofore used, do not form effective bars againstmoisture and vapor and, therefore, do not provide complete protection.Also, they require for their production the use of overwrapping machinesthat are capable of a rate of production greatly below that of thecartoning machines, such as carton erectors, fillers and sealers.Additionally, such overwraps required the use of amounts of filmsubstantially greater in area than the exterior of the cartons enclosedwithin them and, when such film or foil is very thin, they presenteddifficulties in moving through the machine. Tight overwrapping is thechosen method when exacting package appearance is required. However,such tight overwrapping further lowers production speed because of theneed for application of glue in the course of the process.

The present invention is directed to a system and blank for forming anoverwrap type of package in which all of the foregoing shortcomings areeliminated.

It is, thus, one of the objects of the present invention to devisemethods and provide blanks for forming packages of the overwrap typethat are substantially hermetically sealed, to thoroughly protect thebox or package contents and the package walls against atmosphericpenetration, especially atmospheric moisture or vapor, and thus protectboth the contents and the walls of the box or package from deleteriouseffects of such environmental elements.

It is also an object of the present invention to devise methods andprovide blanks to form overwrap type of packages, of the characterdescribed, which may be produced at a rate of speed greatly in excessthan possible with conventional overwrap type of packages.

It is another object of the present invention to devise methods andprovide blanks for forming overwrap type of packages, of the characterdescribed, which are economical in the use of the overwrapping materialand in which the overwrapping material is capable of receiving surfaceprinting and decoration and which will remain on the package after it isopened.

Broadly stated, the present invention employs the basic phenomenon ofmembrane delamination which is described and utilized in my aforesaidpatent for forming the packages of the invention.

More specifically stated. the present invention provides a method forforming an overwrap package having moisture-barrier characteristics froma blank that is struck from a sheet of delaminable material. Suchmaterial comprises a substratum, of conventional packaging materialhaving a degree of porosity as paper board, stiff paper and the like,and a multi-ply covering sheeting which includes inner and outer heatsealable plies or coatings between which is adhesively held a ply ofstiffening material such as metal foil paper or polypropylene film orthe like; which sheeting is delaminably secured to the substratum by amoisture resistent, heatweakenable laminant, such as a micro-crystallinewax blend. The method of the invention includes the steps ofdelaminating at least one select area of the blank, such as theoverlapping flaps of a carton before folding, under the influence ofheat to strip the sheeting from the substratum, and thereafter foldingthe stripped substratum into one selected position, and adhering thestripped sheeting to the sheeting of another blank area of the packageexterior, thereby forming a substantially hermetic sheeting to sheetingseal.

To that end, the stripped folded portions of the substratum may includefoldable gussets connecting other foldable portions of the substratum,with the gussets having a portion of their delaminated sheeting cut awayand removed.

Clearer and more specific details of the packages of the presentinvention and of the methods and blanks by and from which they may beformed, and their foregoing and other objects and advantages, will bemore clearly understood from the accompanying drawings and from thedescription following. It is to be understood, however, that theembodiment of the invention shown in the drawing is intended to be onlyillustrative of the invention and not as limiting the same to thespecific details shown.

In the drawings,

FIG. 1 is a plan view of one end ofa blank formed according to thepresent invention, nested with and abutting one end of a second blankwhich is shown in phantom;

FIGS. 1A, 1B, 1C and 1D show four typical forms of laminations fromwhich the blank may be struck;

FIG. 2 shows, in perspective, one corner of the blank in a first step offormation into a package and an associated apparatus element forproducing the formation step illustrated.

FIG. 3 shows, in perspective, the same corner of the blank of FIG. 2; ata later stage of formation;

FIG. 4 is an elevational view of one side wall of the package and anassociated apparatus mandrel member used in the formation of thepackage;

FIG. 5 is an isometric view of an erected package prior to sealing; and

FIG. 6 is a top plan view of the package at a later stage of formation.

More specifically stated, FIGS. 1A to 1D, inclusive, show four typicalforms of lamination from which blanks according to the present inventionmay be struck. In all four, folding box board, 1, is the preferredsubstratum and a micro-crystalline wax blend, 2, is the preferred heatweakenable laminant which releasably secures the barrier sheetingthereto.

FIG. IA illustrates a barrier sheeting which comprises a lamination of afirst inner heat sealable sheet or film of polyethylene 3; a stiffeningply of metal foil,

such as aluminum foil sheet 4; and a further, outer polyethylene sheet,30. FIG. 1B. shows a barrier sheeting which comprises a first innersheet of polyethylene film, 3, a thin paper sheet, 5; an adhesive layer,6, over paper sheet, 5; an aluminum foil sheet, 4; and an outerpolyethylene sheet, 30.

FIG. 1C shows a barrier sheeting which comprises a first inner sheet ofpolyethylene film, 3; a polypropylene sheet, 7, above it; and a furtherpolyethylene sheet, 30.

The barrier sheeting illustrated in FIG. 1D comprises a first innersheet of polyethylene, 3; a thin paper sheet, 5; and a furtherpolyethylene sheet, 30.

It may here be stated that many other overwrap sheeting combinations maybe employed in which, for instance, heat sealable polyvinyl films may besubstituted for polyethylene, as well as heat sealable lac quers. Theparticular package style described herein requires that the sheeting bethermoplastically adhesive on both sides, but it may be noted that suchcharacteristic would not be required with other packaged styles ifmandrel means could be employed to make pressure contact with all theplies to be fused together.

In FIG. 1, there is shown one end of a blank formed from a lamination,such as detailed above, a blank end being in substantially common,knife-nested relationship with the end of another blank which is shownin phantom. The other end of the blank, which is not shown, is identicalto the end of the blank shown in phantom. The blank is creased andscored for folding into a carton or box to define the various panels andflaps forming the sides and ends of the package. All creases areindicated in the drawings by broken lines and all score lines, which cutthrough the sheeting, by unbroken lines. The arrow X indicates thepreferred grain direction of both the substratum and sheeting; though incertain instances the grain direction could be at an angle of 90 to thatindicated in the drawings.

The panels of the blank comprise a base, 8, a front side wall, 9, a rearside wall, 10, and a top, 11, and a tucking panel, 12. Connected to thebase, 8, is a side panel, 13, which has connected thereto a sealingflap, 14.

Side panel, 13, is connected, at each end, to front and rear side walls,9 and 10, respectively, by a preferably L-shaped gusset, 15. Eachgusset, 15, is connected along one edge to adjacent side wall, 9 or 10,as the case may be, by a crease line, 17. Each gusset, 15, is connectedby its other edge to side panel 13, at its inner end by a crease line,18, and outwardly thereof by a score line, 16, which extends at itsinner end diagonally across gusset, 15, and continues, thereafter,parallel to crease line, 17, to the free edge of the gusset, the scoreline, 16, extending through the sheeting ply.

Gusset, 15, is foldable on a fold line, 19, which is formed to bend in adirection opposite to fold lines, 17 and 18, along which it is foldablerelative to adjacent wall, 9 and 10, and to side panel 13.

FIG. 2 illustrates the treatment of the gusset, 15, at a first stage offormation of the container and shows the portion of the sheetingoverlying the gusset as having been rendered delaminable through theemployment of local heat and the portion 20 thereof outwardly of scoredline 16, as having been removed, to leave a completely denuded gussetarea which is designated in the drawing by stippling. The remainder ofthe delaminated portion of the gusset sheeting curls away from thesubstratum of thc gusset. This is the result of the method utilized inthe local heating of the gusset area which is effected by a block, 100,formed with a serrated gusset contacting surface.

The gusset contacting surface of block, 100, is preferably serrated andcoated with an adhesion-repellent coating, such as the substancecommonly and widely distributed under the trademark of Teflon."

Block 100, which is heated and overlies the entire area of gusset, 15,will cause ply, 2, of the blank, namely the micro-crystalline wax, tomelt, thereby causing a delamination between the sheeting 3 and thesubstratum 1 of the gusset and at the same time will cause the portionof the sheeting outwardly of score lines, 17, to superficially adhere tothe heated, serrated surface of the block, 100, as indicated at 20, fromwhich it may be easily removed, by reason of the serrated surface of theblock by a mating tool not shown. It should be noted that throughout theoperation, when sufficient heat is applied to the gusset, the wax blendlaminant, which melts at Fahrenheit, will, at a higher temperature, loseall of its tack strength and will become fluid and be absorbed in theporosity of the substratum board, so that the sheeting and thesubstratum become instantly and completely nonadhesively separated.

FIG. 3 illustrates a further stage in the formation of the container inwhich the substratum of the gusset, 15, is folded inwardly on fold line19 as side panel, 13, and the adjacent front and rear side walls 9 and10 are erected. The substratum of the gusset, 15, will fold inwardly byreason of the direction of creasing and the pressure applied at the timeof erecting, and also by reason of the direction of the grain of thesubstratum. However, the remainder of the gusset sheeting which has beendelaminated from its substratum and is some what curled away therefromand which has its own stiffness and its own grain direction, will tendto remain static and foldable outwardly on crease 19, and will backfold90 on crease 18, forming an exterior gusset which can be wiped andfolded and adhered to side panel 13, with the outer portion of thegusset sheeting overlying the triangular portion, 23, of the sheetinglying between fold line, 19, therein, and crease line 18 (FIG. 4).

FIG. 4 shows the open topped tray immediately underlying a mandrelforming member 21, the cooperating female forming member of which is notshown. The mandrel reciprocates as the arrow indicates and is here shownremoved from the tray subsequent to the folding of the sheeting gussetby 90, and adhering to the side panels 13. A portion of panel 13 hasbeen torn away to reveal the interior of the tray; also shown is thesubstratum portion 22 of the gusset, disposed in the same directionwithin the pack as the gusset sheeting portion is outside.

The portion of the sheeting gusset that is backfolded by onto itself isdefined by a dotted line and is marked 23.

In heat sealing the corner-staying gussets into position, the followingstages are preferred:

Subsequent to heating the gusset and removing the scrap as shown in FIG.2, and as quickly thereafter as is possible, mandrel 21 forces the blankthrough the cooperating female die member and other members, cooperateto shape the board and sheeting gussets as required. When all the packcorner members are positioned, intensive heat, preferably hot air. islocally applied to the surface of the sheeting gusset and the pack sidewall with which it will be brought into pressure contact. When bothsurfaces have been sufficiently heated, the new adhesive surfaces may bebrought into contact. In practice, it has been found that a wipingaction applied to the sheeting gusset is preferred. Such wiping is besteffected by a Teflon coated flat spring with a radius at the free end,such radius making initial contact along crease l7 and wiping across thewhole of the sheeting gusset. As the mandrel is removed from the tray,the wipers return to their root position.

It should be noted that the sheeting is heat scalable on both sides,therefore an instant bond results from the combination of heat andpressure; it has been found that no pressure dwell-time is required.

FIG. 5 assists in the description of multiple stages of production. Thetray is erected as shown in FIG. 4; the tray corners are securelyadhered and the package ready for filling with product. It is to bepresumed therefore that in FIG. 5 the pack would already contain productand is in one stage of being transported on a series of three endlessconveyors.

The first direction of travel is indicated by a single arrow. In thisdirection the filled pack is transported by spaced pusher members,attached to an endless chain or the like. During transportation, panels14 are splayed 90 outwards from their root position. This issimultaneous with panel 11 being back-folded 90 in relation to its rootposition. Panels 14 may now be brought into range of proximity heatintroduced onto the sheeting surface. An alternative method is to bringpanels 14 into contact with a serrated heated, Teflon coated roller. Ifa roller is employed, the sheeting, once in contact therewith, is pulledinto an arcuate path. Hence it is necessary to employ a co-operatingtool that is seated within the serrations and instantly strips thesheeting from the roller.

Immediately prior to stripping the sheeting from the roller, ablade-like tool may enter between the sheeting 14D and the substratum14, thereby to effect positive separation therebetween. Immediatelythereafter panel substrata 114 are folded inwardly by 90 from the rootposition. The pack in this condition is transferred onto a secondconveyor, substantially as aforedescribed, whereupon panel 12 isdelaminated in a manner similar to panels 14. Immediately thereafter,panel 11 is folded 90 in relation to panel 10, stripped substratum 12 istucked to lie parallel with the interior of panel 9 and strippedsheeting 12D is disposed to lie parallel to the exterior of panel 9.Panel 9 and sheeting 12D may then be heated on those surfaces that willcontact each other, and pressure is applied in the wiping mannerdescribed in FIG. 4.

It should now be understood why the preferred sheeting for the packdescribed herein has a heat scalable surface on both sides. It will beobvious that the fusing of sheeting ll2D to panel 9 does not permit theemployment of a mandrel; therefore the pressure that can be applied islimited. As a consequence it becomes necessary to bring cohesivesurfaces together. It would be impossible to adhere a non-adhesivesurface to achieve the quality of adhesion that results from heatscalable coatings without considerable pressure.

The third and final sealing stage involves another change of directionas shown by the three-part arrow and once again adhesion is caused inthe manner aforedescribed to seal sheeting 14D.

In FIG. 6 there is shown the pack condition immediately prior to thelast stage described with reference to FIG. 5. At this stage margins ofcover panel 11 and sheetings 14D are heated and folded to contact eachother. It should be noted that some structural rigidity is contributedby denuded panels 14, both of which are seen through the torn awayportions of cover 11. Also shown is the gusseted substratum 22.

The pack that has been described is ideally suited for the barrierprotection requirements of dry hygroscopic products. If the interior ofthe pack is coated with a moisture resistant material, then the packwill be suitable for products containing high moisture or even a limitedamount of free liquid. Once the pack is completely assembled, thewrapper is sealed hermetically with the sole exception of four cornerpinholes that appear at the top of the pack. These are breaks in thecontinuity of the sheeting and are equal to the thickness of thesubstratum, this not being the case at any other pack seam, all of whichare totally imperforate. It should be noted, however, that the pinholesin the cover sheeting are backed up by multiple plies of waxed board.

All my previous work on the subject of membrane delamination providedthe opportunity to create separate shapes from unitary sheet materialcomprising a substratum and a delaminable sheeting adhered thereon,provided that the panel(s) that were to be delaminated were alwaysdefined by a fold line. Attachment between the delaminable panel and anopposed panel(s) was required before delamination could take place, suchbeing required prior to altering of the geometry of the stripped board.

These stages in series imposed certain limitations on the number ofgeometric shapes that could be produced. The technique of scoring only aportion of the sheeting in relation to the total panel of which it is apart, makes it possible to create a broader range of three dimensionalshapes. Simply stated, one can score only a select portion of a panelarea, and by so doing make only a select area of the sheeting freeable.Packs employing this technique may be provided with fold lines suitablefor the main pack configuration whilst select areas of the blank may bescored potentially to free the sheeting where required. The freeablesheeting may be cleanly released by the local application of heat. Theboard that is stripped of all or part of its sheeting may be positionedas required and the freed sheeting maintained in reserve to perform alater sealing function. It is apparent that this is readily accomplishedwithout necessarily relying on the fold lines required for the formationof the substratum into pack form. The process technique aforedescribedis obviously applicable to many other pack styles.

What I claim is:

l. A method for forming an overwrapped package, of the characterdescribed, comprising the steps of forming a blank having foldableportions, said blank including a substratum formed of substantiallystiff package forming material and a moisture resistant sheeting havingself-adhering surfaces, delaminably secured to said substratum by amoisture resistant heat weakenable laminant, delaminating at least onefoldable area of the blank under the influence of heat to strip thesheeting from the substratum thereof, folding said stripped substratumarea to a selected position, away from its delaminated sheeting, andthereafter folding the stripped sheeting over and adhering it to thesheeting portion of another blank area on the exterior thereof. tothereby form a sheeting to sheeting seal between said stripped sheetingand said sheeting portion.

2. The method according to claim 1 wherein said sheeting to sheetingadhesion is effected by the application of heat.

3. The method of claim 1, wherein the substratum material is porous toat least partly absorb the laminant material upon the application ofheat.

4. The method of claim 1 wherein said blank foldable area comprises agussetted corner wall which interconnects adjacent wall panels andwherein a score line extends through said sheeting in the gussetted wallregion and defines a detachable area so that, when said delaminating ofsaid foldable area occurs, said detachable area of sheeting separatesfrom the remainder of said delaminated sheeting.

5. A blank for forming an overwrapped package of the character describedcomprising a substratum ply of substantially stiff package formingmaterial and a sheeting ply overlying said substratum and securedthereto by a moisture-resistant heat-weakenable laminant material,whereby said sheeting is delaminable from said substratum by theapplication of heat, said blank including wall panels pre-creased forfolding away from a delaminated portion of said sheeting, at least onearea of the sheeting on said blank being severed from the remainderthereof and detachable from the rest of said blank upon delamination.

6. The blank of claim 5, wherein said heatweakenable laminant materialis of low melting point,

and wherein said substratum comprises porous fibrous material adapted toabsorb the said heat-weakenablc laminant upon application of sufficientheat for melting the same.

7. The blank of claim-5, wherein said sheeting comprises heat-sealableinner and outer surfaces.

8. The blank of claim 5, wherein said sheeting comprises adheringmulti-plies of material including inner and outer plies of heat-scalablefilm and an intermediate ply of stiffening material.

9. The blank of claim 8, wherein said inner and outer plies comprisepolyethylene film.

10. The blank of claim 8 wherein said intermediate ply comprises a sheetof material selected from the group of paper, metal foil andpolypropylene film.

11. The blank of claim 5 wherein said blank comprises a plurality ofpanels defined by fold lines and wherein said severed area is defined bya score line cut completely through said sheeting which crosses one foldline and which is spaced from another fold line for at least a portionof the length of said score line.

12. The blank of claim 5 wherein said substratum includes a base towhich are hinged side panels and a front panel, said pre-creased wallpanels being gussets hinged respectively to said front panel and to oneof said side panels, each of said gussets including a diagonal creaseextending outward from a corner of said base, said severed sheeting areaoverlying a portion of said gusset.

13. The blank of claim 12 wherein said area is severed along a line thatis spaced from one of the lines along which said gusset is hinged to oneof said panels and that crosses said diagonal crease.

1. A method for forming an overwrapped package, of the characterdescribed, comprising the steps of forming a blank having foldableportions, said blank including a substratum formed of substantiallystiff package forming material and a moisture resistant sheeting havingself-adhering surfaces, delaminably secured to said substratum by amoisture resistant heat weakenable laminant, delaminating at least onefoldable area of the blank under the influence of heat to strip thesheeting from the substratum thereof, folding said stripped substratumarea to a selected position, away from its delaminated sheeting, andthereafter folding the stripped sheeting over and adhering it to thesheeting portion of another blank area on the exterior thereof, tothereby form a sheeting to sheeting seal between said stripped sheetingand said sheeting portion.
 2. The method according to claim 1 whereinsaid sheeting to sheeting adhesion is effected by the application ofheat.
 3. The method of claim 1, wherein the substratum material isporous to at least partly absorb the laminant material upon theapplication of heat.
 4. The method of claim 1 wherein said blankfoldable area comprises a gussetted corner wall which interconnectsadjacent wall panels and wherein a score line extends through saidsheeting in the gussetted wall region and defines a detachable area sothat, when said delaminating of said foldable area occurs, saiddetachable area of sheeting separates from the remainder of saiddelaminated sheeting.
 5. A blank for forming an overwrapped package ofthe character described comprising a substratum ply of substantiallystiff package forming material and a sheeting ply overlying saidsubstratum and secured thereto by a moisture-resistant heatweakenablelaminant material, whereby said sheeting is delaminable from saidsubstratum by the application of heat, said blank including wall panelspre-creased for folding away from a delaminated portion of saidsheeting, at least one area of the sheeting on said blank being severedfrom the remainder thereof and detachable from the rest of said blankupon delamination.
 6. The blank of claim 5, wherein said heat-weakenablelaminant material is of low melting point, and wherein said substratumcomprises porous fibrous material adapted to absorb the saidheat-weakenable laminant upon application of suFficient heat for meltingthe same.
 7. The blank of claim 5, wherein said sheeting comprisesheat-sealable inner and outer surfaces.
 8. The blank of claim 5, whereinsaid sheeting comprises adhering multi-plies of material including innerand outer plies of heat-sealable film and an intermediate ply ofstiffening material.
 9. The blank of claim 8, wherein said inner andouter plies comprise polyethylene film.
 10. The blank of claim 8 whereinsaid intermediate ply comprises a sheet of material selected from thegroup of paper, metal foil and polypropylene film.
 11. The blank ofclaim 5 wherein said blank comprises a plurality of panels defined byfold lines and wherein said severed area is defined by a score line cutcompletely through said sheeting which crosses one fold line and whichis spaced from another fold line for at least a portion of the length ofsaid score line.
 12. The blank of claim 5 wherein said substratumincludes a base to which are hinged side panels and a front panel, saidpre-creased wall panels being gussets hinged respectively to said frontpanel and to one of said side panels, each of said gussets including adiagonal crease extending outward from a corner of said base, saidsevered sheeting area overlying a portion of said gusset.
 13. The blankof claim 12 wherein said area is severed along a line that is spacedfrom one of the lines along which said gusset is hinged to one of saidpanels and that crosses said diagonal crease.